Multilayer film for producing laminates

Abstract

Multilayer film (1) for producing laminates (2), preferably smart cards (3), wherein the multilayer film (1) comprises at least one polymer layer (4) and at least one adhesion promoter layer (5), wherein the at least one polymer layer (4) comprises or consists of at least one bio-based polymer.

Description

[0001] Multi-layered film for manufacturing laminates

[0002] The present disclosure relates to a multilayer film, a laminate with such a multilayer film and methods for producing such a multilayer film and such a laminate.

[0003] Such multilayer films and / or laminates can be used, for example, in smart cards.

[0004] A smartcard can also be called a chip card, key card, or integrated circuit card.

[0005] Examples of smart cards include bank cards, credit cards, identity documents, membership cards, chip cards and similar items.

[0006] Bank cards typically have several layers, such as overlay, core, and inlay. Individual, multiple, or all of these layers can be constructed from foils.

[0007] Common materials for the films and layers of smart cards include polyvinyl chloride (PVC), polyester, and polycarbonate (PC). PVC is preferred for bank cards due to the following properties:

[0008] - Transparency,

[0009] - high flexural strength ,

[0010] - good recovery behavior after deformation,

[0011] - Suitable temperature range for the application between approximately -10°C and +70°C,

[0012] - good printability ,

[0013] - Laminating capability of multiple layers at temperatures of approximately 120 °C and - favorable raw material price.

[0014] A disadvantage of PVC is that its production is not environmentally friendly or sustainable due to the chlorine chemistry involved.

[0015] The object of this disclosure is therefore to at least partially overcome the disadvantages of the prior art and to disclose an improved film for smart cards, which is characterized in particular by greater environmental friendliness and sustainability. The object further is to disclose a laminate with such a multilayer film and a method for producing such a multilayer film and such a laminate. This object is achieved by the features of claims 1, 11, 12 and 13.

[0016] This problem is solved by means of a multilayer film according to claim 1, namely a multilayer film for producing laminates, preferably smartcards, wherein the multilayer film has at least one polymer layer and at least one adhesion promoter layer, wherein the at least one polymer layer has at least one bio-based polymer or consists thereof.

[0017] A multilayer film can be a film with more than one layer; in other words, a film with two, three, or more layers. A bio-based polymer is a polymer produced using renewable raw materials. This avoids environmentally harmful and unsustainable raw material sources such as fossil fuels and achieves greater sustainability through a significantly smaller carbon footprint. Bio-based and non-bio-based polymers can be distinguished, particularly by their content of [missing information]. 14 Carbon isotope. For this purpose, methods from the following standards can be used, for example:

[0018] - ISO 16620-1:2015, Publication date: 02.04.2025, Plastics — Biobased content — Part 1: General principles, available at https: / / www.austrian-standards.at / de / shop / iso-16620-1-2015-2015-04-02~p2129804

[0019] - DIN EN 16785-1, issue date March 2016, Bio-based products - Bio-based content - Part 1: Determination of bio-based content using radiocarbon and elemental analysis; German version EN 16785-1:2015, available at https: / / www.austrianstandards.at / de / shop / din-en-16785-1-2016-03~p2215481

[0020] - ASTM D6866-22, Standard Test Methods for Determining the

[0021] Biobased Content of Solid, Liquid, and Gaseous Samples Using Radiocarbon Analysis, available at https: / / store. astm. org / d6866-22. html

[0022] - Further standards are cited by Hydroisotop, see here

[0023] The standards cited above are hereby incorporated into the present disclosure by reference.

[0024] In a preferred embodiment of the multilayer film, it can be provided that the at least one polymer layer comprises or consists of at least one biodegradable polymer.

[0025] In a preferred embodiment of the multilayered

[0026] The film may be designed to be at least one bio-based polymer and at least one biodegradable polymer.

[0027] Bio-based polymers may have a melting point and / or Vicat softening temperature that is too high for further processing into a laminate and / or smartcard. For example, bonding multilayer films and / or laminates at temperatures of 120°C may be difficult or impossible. Bonding of multilayer films and / or laminates can be facilitated and / or made possible with the aid of an adhesion promoter layer.

[0028] The multilayer film with at least one polymer layer and at least one adhesion promoter layer can be flexible yet stiff enough to be used for smart cards.

[0029] Further advantageous embodiments are defined in the dependent claims.

[0030] According to a preferred embodiment of the multilayer film, it can be provided that the multilayer film, preferably the at least one polymer layer and / or the at least one adhesion promoter layer, comprises at least one of the following substances:

[0031] - at least one additive, preferably at least one laser additive, particularly preferably at least one laser pigment ,

[0032] - at least one stabilizer,

[0033] - at least one filler f ,

[0034] - at least one reinforcing material, preferably talc, glass beads, wollastonite, muscovite, fibrous material, particularly preferably glass fibers, plate-shaped material and / or spherical material,

[0035] - at least one color pigment. The desired stabilization of the at least one bio-based polymer for processing and use can be achieved with stabilizers and additives known from the literature.

[0036] Reinforcing materials, well-known to plastics experts, serve to increase flexural stiffness. Examples of reinforcing materials include talc, glass beads, wollastonite, muscovite, glass fibers, or other fibrous, platelet-shaped, or spherical particles. For instance, a film made of pure polyamide 11, or PA11 for short, has a modulus of elasticity of approximately 900 MPa. In a preferred embodiment, a mass fraction of 15% talc can be added to the PA11, which can increase the modulus of elasticity to approximately 2100 MPa.

[0037] According to a preferred embodiment of the multilayer film, it can be provided that the multilayer film, preferably the at least one polymer layer and / or the at least one adhesion promoter layer, has a modulus of elasticity above 1000 MPa, preferably above 1500 MPa, particularly preferably between 2000 MPa and 2200 MPa.

[0038] According to a preferred embodiment of the multilayer film, it can be provided that the multilayer film, preferably the at least one polymer layer and / or the at least one adhesion promoter layer, has an opacity of over 20%, preferably over 40%, particularly preferably over 50%.

[0039] Opacity can be understood as the opposite of transparency. Opacity can be the inverse of the transmission of incident light through a material and / or the difference between 100% and the percentage of transparency, specifically opacity [%] = 100 - transparency [%]. Opacity is important for information on or attached to multilayer films, for example, prints and similar elements on a smartcard made of multiple layers of multilayer film.

[0040] According to a preferred embodiment of the multilayer film, it can be provided that the at least one polymer layer has a layer thickness between 0.04 mm and 0.50 mm, preferably between 0.06 mm and 0.30 mm, and / or the at least one adhesion promoter layer has a layer thickness between 3 pm and 30 pm, preferably between 10 pm and 20 pm.

[0041] Such layer thicknesses may preferably be provided to provide sufficient mechanical properties such as flexural strength and / or bond strength between the at least one polymer layer and the at least one adhesion promoter layer and / or desired optical properties such as transparency or opacity.

[0042] According to a preferred embodiment of the multilayer film, it can be provided that the multilayer film, preferably the at least one polymer layer and / or the at least one adhesion promoter layer, is printable and / or laminateable and / or laser-printable.

[0043] According to a preferred embodiment of the multilayer

[0044] The foil may be designed so that

[0045] - the mass fraction of the at least one bio-based polymer in the multilayer film is above 60%, preferably above 65% or above 70% or above 80% or above 90% or above 95% or above 97%, and / or

[0046] - the mass fraction of the at least one bio-based polymer in the at least one polymer layer is greater than 75%, preferably greater than 80% or greater than 90% or greater than 95% or greater

[0047] 97% , lies and / or

[0048] - the mass fraction of the at least one bio-based polymer and / or at least one other bio-based polymer in the at least one adhesion promoter layer is at least 5%, preferably between 5% and 25% or between 5% and 10%.

[0049] In a preferred embodiment of the multilayer film, it can be provided that

[0050] - the mass fraction of a bio-based polymer or all bio-based polymers in the multilayer film is above 60%, preferably above 65%, or above 70%, or above 80%, or above 90%, or above 95%, or above 97%, and / or

[0051] - the mass fraction of a bio-based polymer or all bio-based polymers in the at least one polymer layer is above 75%, preferably above 80% or above 90% or above 95% or above 97%, and / or

[0052] - the mass fraction of a bio-based polymer or all bio-based polymers in the at least one adhesion promoter layer is at least 5%, preferably between 5% and 25% or between 5% and 10%.

[0053] In a preferred embodiment of the multilayer film, it can be provided that the mass fraction of the at least one bio-based polymer in the multilayer film, preferably in the at least one polymer layer, is above 90%, preferably above 95%, particularly preferably above 97%.

[0054] Despite the addition of substances such as stabilizers, the mass fraction of bio-based polymer in the multilayer film can still exceed 90%, and at least one bio-based polymer can be processed effectively, for example, by extrusion. This approach offers advantages in terms of sustainability as well as processing and use of the multilayer film.

[0055] According to a preferred embodiment of the multilayer film, it can be provided that the at least one polymer layer

[0056] - at least one bio-based polyamide, preferably bio-based polyamide 11 and / or bio-based polyamide 1010, and / or

[0057] - comprising or consisting of at least one, preferably partially or completely, bio-based copolymer, preferably of bio-based polyamide 11 and / or bio-based polyamide 1010.

[0058] Polyamide 11 can be referred to as PA11 and polyamide 1010 can be referred to as PA 1010.

[0059] PA11 can refer to pure polyamide 11, CAS No. 25035-04-5, which is sold, for example, by Arkema under the brand name Rilsan®, and / or copolymers containing PA11 components.

[0060] PA1010 can refer to pure polyamide, CAS No. 28774 - 87- 0, which is sold, for example, by Arkema under the brand name Rilsan®, and / or copolymers containing PA1010.

[0061] Furthermore, compounds of PA11 with fillers as well as blends of PA11 with other polymers can also be used.

[0062] Bio-based polyamide can be produced from the castor bean plant and can therefore be entirely bio-based. This results in greater sustainability through a significantly smaller CO2 footprint. Further investigations have shown that the combination of PA11 and an adhesion promoter layer can represent a very good combination of properties for use as a single-layer film in smart cards, and / or that these single-layer films can be preferably produced by co-extrusion.

[0063] In a preferred embodiment of the multilayer film, it can be provided that the multilayer film can be produced by means of coextrusion.

[0064] Bio-based polyamide can have a melting point of approximately 185 °C and / or a Vicat softening temperature above 150 °C.

[0065] The at least one polymer layer can, for example, have a sublayer of PA11 and another sublayer of PA1010, or even just a sublayer of a mixture of PA11 and PA1010. In another example, the at least one polymer layer can have a sublayer of a copolymer, wherein the copolymer contains or consists of PA11 and / or PA1010. A combination of these examples is also conceivable. Furthermore, it can be provided that all of the polymers present, or only individual polymers, or only a single polymer are at least partially or completely bio-based.

[0066] In a preferred embodiment of the multilayer film, it can be provided that the at least one polymer layer comprises or consists of at least one bio-based polylactide, or PLA for short.

[0067] According to a preferred embodiment of the multilayer film, it can be provided that at least one

[0068] Adhesion promoter layer - at least a modified polyolefin, preferably at least a maleic anhydride-modified polyolefin, and / or

[0069] - contains or consists of at least a polycarbonate, preferably at least a bio-based polycarbonate.

[0070] A modified polyolefin can be a polyolefin in which a functional group is reacted.

[0071] The modification of at least one modified polyolefin can form a compound with at least one bio-based polymer in the melting phase.

[0072] Maleic anhydride is preferably used as the functional group, which can be grafted onto a polyolefin or copolymerized.

[0073] The polyolefin in the at least one adhesion promoter layer can be selected such that it can form a good bond to at least one polymer layer, to at least one further adhesion promoter layer, to at least one further multilayer film and / or to at least one laminate, preferably within a smartcard, at lamination temperatures of approximately 120 °C.

[0074] Surprisingly, it has been shown that the addition of a bio-based polycarbonate to the maleic anhydride-modified polyolefin leads to a significant improvement in the adhesion of printing inks to a film layer made from this mixture.

[0075] A further increase in the adhesion of the printing inks to a film layer made from said mixture is achieved through pretreatment methods known to experts, such as corona treatment.

[0076] Flame or plasma pretreatment is achieved. In a preferred embodiment of the multilayer film, it can be provided that a maleic anhydride-modified polyolefin is used with a bio-based polycarbonate as an adhesion promoter layer.

[0077] A maleic anhydride-grafted polyolefin-based elastomer, POE-MSA, can have a type with a Vicat softening temperature of 62°C according to ASTM D1525.

[0078] The bio-based polycarbonate can be produced from I sosorbide.

[0079] In a preferred embodiment of the multilayer film, it can be provided that the at least one adhesion promoter layer comprises or consists of at least one bio-based polymer, preferably the same at least one bio-based polymer as in the at least one polymer layer and / or at least one further component of the at least one polymer layer can be provided in the at least one adhesion promoter layer.

[0080] In a preferred embodiment of the multilayer film, it can be provided that the at least one adhesion promoter layer has the same components as the at least one polymer layer up to a mass fraction of 20%.

[0081] According to a preferred embodiment of the multilayer film, it can be provided that the mass fraction of the at least one modified polyolefin in the at least one adhesion promoter layer is between 50% and 95%, preferably between 70% and 90%, and / or the mass fraction of the at least one polycarbonate in the at least one adhesion promoter layer is between 5% and 50%, preferably between 10% and 30%.

[0082] In a preferred embodiment of the multilayer film, the mixing ratio of the mass fractions of the modified polyolefin, preferably of the at least one maleic anhydride-modified polyolefin, and of the at least one polycarbonate, preferably of the at least one bio-based polycarbonate, may be between 95:5 and 50:50, particularly preferably 90:10 and 70:30.

[0083] Tests have shown that the adhesion between two polymer layers of pure PA11, type Rilsan® Besno TL NB, pressed in a press at 125 °C and 5 bar for 5 minutes, is zero. Under the same pressing conditions, the adhesion between said two polymer layers with an adhesion promoter layer disclosed herein, consisting of 80% POE-MSA and 20% bio-based polycarbonate, is more than 20 N / cm, which is sufficient for smartcard applications.

[0084] Furthermore, protection is sought for a laminate, preferably a smartcard, comprising at least two interconnected layers, wherein at least one of the at least two layers comprises or consists of at least a multilayer film disclosed herein.

[0085] In a preferred embodiment of the laminate, it can be provided that the laminate is printable and / or laminating and / or laser-markable.

[0086] In a preferred embodiment of the laminate, it can be provided that at least two, at least three, several, or all layers of the laminate comprise or consist of at least one multilayer film disclosed herein. Furthermore, protection is sought for a method for producing a multilayer film, preferably a multilayer film disclosed herein, comprising at least the following process steps:

[0087] - Providing at least one polymer material and at least one adhesion promoter and

[0088] - Combining, preferably co-extruding, the at least one polymer material and the at least one adhesion promoter in the form of the multilayer film with at least one polymer layer and at least one adhesion promoter layer, wherein the at least one polymer layer comprises or consists of at least one bio-based polymer.

[0089] Due to the co-extrusion of at least one adhesion promoter layer on at least one side, preferably on at least two sides, of the multilayer film, the multilayer film can be printable and / or laminated.

[0090] Furthermore, protection is sought for a process for manufacturing a laminate, preferably a laminate disclosed herein, comprising at least the following process steps:

[0091] - Providing a first layer and at least a second layer, wherein the first layer comprises or consists of at least a multilayer film, wherein the multilayer film comprises at least a polymer layer and at least one adhesion promoter layer, wherein the at least one polymer layer comprises or consists of at least a bio-based polymer, preferably wherein the at least one multilayer film is produced by a process disclosed herein, and

[0092] - Joining the first layer and at least one second layer, preferably under pressure and / or

[0093] Temperature influence. For the sake of completeness, it should be noted that in the course of describing this disclosure, the numerical terms used, such as one, two, three, and the like, generally only describe the minimum quantity of a feature of the disclosed multilayer film. Individual features or components can, of course, also be present in larger numbers. For example, disclosed multilayer films can have more than one polymer layer, more than one adhesion promoter layer, more than one bio-based polymer, etc. In this sense, the numerical term "one" should, where appropriate, be understood as meaning at least one, etc.

[0094] Further details and advantages of preferred design examples are explained in more detail below with reference to the figure description and the drawings. These show:

[0095] Fig. 1: a schematic representation of an embodiment of a multilayer film;

[0096] Fig. 2: a schematic representation of another embodiment of a multilayer film;

[0097] Fig. 3: a schematic representation of an embodiment of a laminate, preferably a smartcard.

[0098] Fig. 1 shows a schematic representation of a

[0099] Example of a multilayer film 1.

[0100] Fig. 1 shows a multilayer film 1 for producing laminates 2, preferably smartcards 3, wherein the multilayer film 1 comprises at least one polymer layer 4 and at least one adhesion promoter layer 5, wherein the at least one polymer layer 4 comprises or consists of at least one bio-based polymer. Fig. 1 shows various layer thicknesses 6, 7 of the at least one polymer layer 4 and the at least one adhesion promoter layer. Preferably, the at least one polymer layer 4 has a layer thickness 6 between 0.04 mm and 0.50 mm, preferably between 0.06 mm and 0.30 mm, and / or the at least one adhesion promoter layer 5 has a layer thickness 7 between 3 pm and 30 pm, preferably between 10 pm and 20 pm.

[0101] In a preferred embodiment of the multilayer film, it can be provided that the multilayer film has at least one polymer layer and at least one outer adhesion promoter layer or at least two outer adhesion promoter layers.

[0102] In a preferred embodiment, it can be provided that the at least one bio-based polymer is PA11 and / or the at least one polymer layer is bonded to at least one adhesion promoter layer, preferably by coextrusion.

[0103] Fig. 2 shows a schematic representation of another

[0104] From an example of a multilayer film 1 .

[0105] In a preferred embodiment, it can be provided that the at least one bio-based polymer is PA11 and the at least one polymer layer, preferably on opposite sides, is connected to at least two adhesion promoter layers, preferably by coextrusion.

[0106] Fig. 3 shows a schematic representation of a

[0107] From an exemplary representation of a laminate 2, preferably a smartcard 3. Fig. 3 shows a laminate 2, preferably a smartcard 3, comprising at least two interconnected layers 8, wherein at least one of the at least two layers 8 comprises or consists of at least a multilayer film 1 according to claim 1.

[0108] Smartcards can typically consist of several layers 8, as shown for example in Fig. 3:

[0109] - a preferred transparent film as an overlay 9

[0110] - a foil, preferably colored with an opaque and / or solid color, as core 10, wherein the core layer 8,11 may be printed,

[0111] - a foil, preferably colored in an opaque manner and / or opaque, as inlay 13, wherein the inlay layer 8,13 may contain at least one embedded antenna 12.

[0112] A smartcard 3 can be structured as follows, for example as in Fig. 3: Overlay layer 8,9, core layer 8,11, inlay layer 8,13, 2nd core layer 8,11 and 2nd overlay layer 8,9.

[0113] Thus, a smartcard 3 can have a symmetrical structure from the outside in or vice versa.

[0114] The overlay 9 can be used to protect the print 10 on the core 11 from scratches.

[0115] The Core 11 can be printed using offset, screen printing and / or digital printing.

[0116] The inlay 13 can be the carrier layer for the antenna 12, so that contactless communication with a transmitter is possible.

[0117] A magnetic stripe 14 can be applied to at least one side, preferably the back, of the smartcard 3, so that the smartcard 3 can be read by means of a magnetic reader. A module can be embedded on at least one side, preferably the front, of the smartcard 3, which has contacts for a connection to a reader and a chip with the programmed card information.

[0118] After laminating all layers 8 of the smartcard 3, an area for the module can be provided, preferably milled out, the area extending to the antenna 12 of the inlay 13. The module is then attached, preferably glued, into this provided, preferably milled, space and contacted with the antenna 12. The contacting of the module, preferably the chip, with the antenna 12 can be accomplished using hot melt foils containing metallic particles.

[0119] Layers 8, for example Inlay 13 and Core 11, may contain color pigments to achieve a certain opacity.

[0120] A white color can be achieved, for example, with titanium dioxide pigments.

[0121] Other mineral white pigments, such as chalk, shell limestone or similar, can be used for coloring.

[0122] Opacity can be increased by adding polymers with a refractive index different from that of PA11. A 0.4 mm thick film of pure PA11 has an opacity of 16%, while adding 10% of polylactic acid (PLA) increases the opacity to 46%.

[0123] In a preferred embodiment, it can be provided that - at least one multilayer film 1, preferably at least one polymer layer 4 and / or at least one adhesion promoter layer 5, and / or

[0124] - at least a laminate and / or

[0125] - at least one layer of at least one laminate is a compound, in other words a composite or a blend, wherein the compound comprises at least one of the following substances:

[0126] - at least two polymers,

[0127] - at least one bio-based polymer,

[0128] - at least two bio-based polymers,

[0129] - at least one, preferably bio-based, polyamide, particularly preferably PA11, wherein preferably the at least one polyamide has a mass fraction in the compound of over 50%,

[0130] - at least one, preferably bio-based, polylactide.

[0131] The overlay layers 8,9 in Fig. 3 can preferably be designed as 2-layer films, for example with a transparent PAll layer and an adhesion promoter layer.

[0132] The core layers 8,11 and / or the inlay layer 8,13 in Fig. 3 can be designed as 2-layer films and / or as 3-layer films.

[0133] The thickness of the adhesion promoter layer can preferably be between 3 pm and 30 pm, preferably between 10 pm and 20 pm.

[0134] In a preferred embodiment, a laminate or a smartcard can be designed to be laser-marked.

[0135] It may be possible to incorporate laser additives into a transparent

[0136] Overlay layers 8 and 9 are to be added. In a preferred embodiment of the multilayer film 1, preferably an overlay layer 8 or 9, it can be provided that

[0137] - comprising at least one polymer layer 4 having a mass fraction of at least 90% polymer, preferably polyamide 11 with a mass fraction of bio-based polyamide 11 of at least 90%, and / or

[0138] - which at least one polymer layer 4 has a mass fraction of 5% of laser additive .

[0139] For example, if the mass fraction of bio-based polyamide 11 in the total amount of polyamide 11 is 90% and the mass fraction of polyamide 11 in polymer layer 4 is 90%, then the polymer layer has a mass fraction of 81% of bio-based polyamide 11.

[0140] In a preferred embodiment of the multilayer film 1, preferably an overlay layer 8, 9, it can be provided that

[0141] - comprising at least one adhesion promoter layer 5 comprising a mass fraction of at least 75% polyolefin, preferably at least one maleic anhydride-modified polyolefin, and / or

[0142] - comprising at least one adhesion promoter layer 5 comprising a mass fraction of polycarbonate between 15% and 25%, preferably polycarbonate with a mass fraction of bio-based polycarbonate of at least 30%, particularly preferably between 35% and 45%.

[0143] In a preferred embodiment of the multilayer film 1, preferably an inlay layer 8, 13, it can be provided that

[0144] - the at least one polymer layer 4 comprising a mass fraction of at least 75% of polymer, preferably polyamide 11 with a mass fraction of bio-based polyamide 11 of over 90%, and / or - the at least one polymer layer 4 comprising a mass fraction between 12% and 17% of an additive, a stabilizer, a filler or a reinforcing agent, preferably talc, and / or

[0145] - which at least one polymer layer 4 has a mass fraction of between 4% and 8% of a color pigment, preferably titanium dioxide.

[0146] For example, if the mass fraction of bio-based polyamide 11 in the total amount of polyamide 11 is 90% and the mass fraction of polyamide 11 in polymer layer 4 is 75%, then the polymer layer has a mass fraction of 67.5% of bio-based polyamide 11.

[0147] In a preferred embodiment of the multilayer film 1, preferably an inlay layer 8, 13, it can be provided that

[0148] - the at least one adhesion promoter layer 5, preferably the at least two adhesion promoter layers 5 each, comprising a mass fraction of at least 75% of polyolefin, preferably of at least one maleic anhydride-modified

[0149] polyolefin, contains and / or

[0150] - comprising at least one adhesion promoter layer 5, preferably at least two adhesion promoter layers 5 each, a mass fraction of polycarbonate between 15% and 25%, preferably polycarbonate with a mass fraction of bio-based polycarbonate of at least 30%, particularly preferably between 35% and 45%.

[0151] In a preferred embodiment of the multilayer film 1, preferably a core layer 8, 11, it can be provided that

[0152] - comprising at least one polymer layer 4 comprising a mass fraction of at least 75% of polymer, preferably polyamide 11 with a mass fraction of bio-based polyamide 11 of over 90%, and / or - comprising at least one polymer layer 4 comprising a mass fraction between 12% and 17% of an additive, a stabilizer, a filler or a reinforcing agent, preferably talc, and / or

[0153] - comprising at least one polymer layer 4 having a mass fraction of between 4% and 8% of a color pigment, preferably titanium dioxide.

[0154] In a preferred embodiment of the multilayer film 1, preferably a core layer 8, 11, it can be provided that

[0155] - comprising at least one adhesion promoter layer 5, preferably at least two adhesion promoter layers 5 each, a mass fraction of over 75% of polyolefin, preferably of at least one maleic anhydride-modified

[0156] polyolefin, contains and / or

[0157] - comprising at least one adhesion promoter layer 5, preferably at least two adhesion promoter layers 5 each, comprising a mass fraction of between 15% and 25% of polycarbonate, preferably polycarbonate with a mass fraction of bio-based polycarbonate of at least 30%, particularly preferably between 35% and 45%.

[0158] PA11 is essentially laser-transparent to a laser with a wavelength of 1064 nm, meaning that the laser light passes through a layer of PA11 without causing a change in color.

[0159] By adding laser additives, such as laser pigments with the brand name Iriotec® from Merck, carbon black pigments or other color pigments, the laser energy can be absorbed into a layer of PA11 and lead to a change in color.

[0160] In PA11, in addition to the degradation of the polymer chains with a resulting darkening, foaming with a corresponding lightening can also occur in the lasered areas. Therefore, achieving high contrast with a clear black coloration is difficult in PA11.

[0161] It is possible to incorporate laser pigments into the adhesion promoter layer, preferably one based on polyolefins. Polyolefins are preferred here because they cause a dark discoloration rather than foaming. The laser beam can thus pass through a substantially laser-transparent PAl layer and only results in a dark color change in the lasered areas within a subsequent adhesion promoter layer.

[0162] A laminate and / or a smartcard may possess features commonly known for films used in the manufacture of smartcards. For example, at least one layer of the laminate may be printed. The print may be positioned between two layers and / or layers of the laminate and / or the smartcard for security reasons.

[0163] In a preferred embodiment, the print 10 can be protected by a transparent film.

[0164] In a preferred embodiment, a magnetic strip 14 can be applied to a laminate 2 and / or an antenna 10 can be embedded in a laminate and / or a module for data transmission can be provided in a laminate.

[0165] Although the preceding description has been written with a certain degree of detail, it should be noted that many changes can be made to the details of the construction of the exemplary embodiments and the arrangement of their components without departing from the basic concept and scope of this disclosure. It is understood that a multilayer film, a laminate, a smart card, or a method for producing a multilayer film, a laminate, or a smart card is not limited to the exemplary embodiments presented here for illustrative purposes.

[0166] All described examples of execution can, if technically possible, be combined with each other and / or supplemented by individual features of other examples of execution.

[0167] Reference character list:

[0168] 1 multi-layered film

[0169] 2 Laminat

[0170] 3 Smartcard

[0171] 4 polymer layer

[0172] 5 bonding layer

[0173] 6. Layer thickness of the polymer layer

[0174] 7 Layer thickness of the adhesion promoter layer

[0175] 8 layers

[0176] 9 Overlay

[0177] 10 Print

[0178] 11 Core

[0179] 12 Antenna

[0180] 13 Inlay

[0181] 14 magnetic strips

Claims

Patent claims 1. Multilayer film (1) for producing laminates (2), preferably smartcards (3), characterized in that the multilayer film (1) has at least one polymer layer (4) and at least one adhesion promoter layer (5), wherein the at least one polymer layer (4) has at least one bio-based polymer or consists thereof.

2. Multilayer film (1) according to claim 1, characterized in that the multilayer film (1) , preferably the at least one polymer layer (4) and / or the at least one adhesion promoter layer (5) , comprises at least one of the following substances: - at least one additive, preferably at least one Laser additives, especially preferably at least one Laser pigment - at least one stabilizer, - at least a filler, - at least one reinforcing material, preferably talc, glass beads, wollastonite, muscovite, fibrous material, particularly preferably glass fibers, plate-shaped material and / or spherical material, - at least one color pigment.

3. Multilayer film (1) according to claim 1 or 2, characterized in that the multilayer film (1), preferably the at least one polymer layer (4) and / or the at least one adhesion promoter layer (5), has a modulus of elasticity above 1000 MPa, preferably above 1500 MPa, particularly preferably between 2000 MPa and 2200 MPa.

4. Multilayer film (1) according to one of the preceding claims, characterized in that the multilayer film (1), preferably the at least one polymer layer (4) and / or the at least one adhesion promoter layer (5), has an opacity of over 20%, preferably over 40%, particularly preferably over 50%.

5. Multilayer film (1) according to one of the preceding claims, characterized in that the at least one polymer layer (4) has a layer thickness (6) between 0.04 mm and 0.50 mm, preferably between 0.06 mm and 0.30 mm, and / or the at least one adhesion promoter layer (5) has a layer thickness (7) between 3 pm and 30 pm, preferably between 10 pm and 20 pm.

6. Multilayer film (1) according to one of the preceding claims, characterized in that the multilayer film (1), preferably the at least one polymer layer (4) and / or the at least one adhesion promoter layer (5), is printable and / or laminateable and / or laser-markable.

7. Multilayer film (1) according to one of the preceding claims, characterized in that - the mass fraction of the at least one bio-based polymer in the multilayer film (1) is above 60%, preferably above 65% or above 70% or above 80% or above 90% or above 95% or above 97%, and / or - the mass fraction of the at least one bio-based polymer in the at least one polymer layer is above 75%, preferably above 80% or above 90% or above 95% or above 97%, and / or - the mass fraction of at least one bio-based polymer and / or at least one other bio-based polymer Polymers in which at least one adhesion promoter layer is present at at least 5%, preferably between 5% and 25% or between 5% and 10%.

8. Multilayer film (1) according to one of the preceding claims, characterized in that the at least one polymer layer (4) - at least one bio-based polyamide, preferably bio-based polyamide 11 and / or bio-based polyamide 1010, and / or - comprising or consisting of at least one, preferably partially or completely, bio-based copolymer, preferably of bio-based polyamide 11 and / or bio-based polyamide 1010.

9. Multilayer film (1) according to one of the preceding claims, characterized in that the at least one adhesion promoter layer (5) - at least a modified polyolefin, preferably at least a maleic anhydride-modified Polyolefin, and / or - contains or consists of at least a polycarbonate, preferably at least a bio-based polycarbonate.

10. Multilayer film (1) according to the preceding claim, characterized in that the mass fraction of the at least one modified polyolefin in the at least one adhesion promoter layer (5) is between 50% and 95%, preferably between 70% and 90%, and / or the mass fraction of the at least one polycarbonate in the at least one adhesion promoter layer (5) is between 5% and 50%, preferably between 10% and 30%.

11. Laminate (2) , preferably smartcard (3) , comprising at least two interconnected layers (8) , wherein at least one of the at least two layers (8) comprises or consists of at least a multilayer film (1) according to claim 1.

12. Method for producing a multilayer film (1), preferably according to claim 1, comprising at least the following process steps: - Providing at least one polymer material and at least one adhesion promoter and - Combining, preferably co-extruding, the at least one polymer material and the at least one adhesion promoter in the form of the multilayer film (1) with at least one polymer layer (4) and at least one adhesion promoter layer (5), wherein the at least one polymer layer (4) comprises or consists of at least one bio-based polymer.

13. Method for producing a laminate (2), preferably according to claim 11, comprising at least the following process steps: - Providing a first layer (8) and at least a second layer (8), wherein the first layer (8) has or consists of at least a multilayer film (1), wherein the multilayer film (1) has at least a polymer layer (4) and at least a has an adhesion promoter layer (5), wherein the at least one polymer layer (4) has or consists of at least one bio-based polymer, preferably wherein the at least one multilayer film (1) is produced by a method according to claim 12, and - Joining the first layer (8) and the at least one second layer (8), preferably under pressure and / or temperature influence.

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